Domain Structures and Phase Transitions of the Relaxor-Based Piezo-/Ferroelectric (1-x)Pb(Zn_(1/3)Nb)_(2/3))O_3-xPbTiO_3 Single Crystals

摘要

The domain structures and phase transitions of therelaxor-based piezo-/ ferroelectric (1-x)Pb(Zn_(1/3)Nb)_(2/3))O_3-xPbTiO_3 single crystals, grownfrom high temperature solutions, have been studied by polarizedlight microscopy. The PZN crystals show domains of trigonalsymmetry and a diffused phase transition of relaxor type. ThePZNT91/9 (x=0.09) crystals exhibit complex domain structureswith coexistence of the trigonal and tetragonal domains at roomtemperature, resulting from a distribution of Ti~(4+)concentration in the individual domains. The domain structures,the sequence and temperature of phase transitions have beeninterpreted in relation to the morphotropic phase boundary (MPB)behavior of te PZN-PT system. It is shown that analysis of thedomain structure and in situ studies of local phase transitionprovide valuable information on the chemical composition andproperties of the PZNT crystals around MPB. This informationwill have relevance to the electromechanical transducerapplications of these innovative piezocrystals.